smith



Hu-'inl 5ta-tet @anni J. B. SMITH, OF` MILWAUKEE, WISCONSIN, ASSIGNOR 'IO HIMSELF AND GEORGE CHITTENDEN, OF CHICAGO, ILLINOIS.

Leners Baum No. 87,717, dazed Merch. 9, 1869.

IMPROVEMENT IN SCREW-,ROUES AND LOCK-NUTS.

. *dab-* l 'rho Schedule 'xerox-na to in these Letters Paume and making part of the sam To allvwhpmc't ma/y concern:

Be it known that I, J. B. SMITH, of the city ofMilwaukee, and State of Wisconsin, have invented a new and useful Improvement in Screw-Bolts and Nuts; and I do hereby declare that the following isfa full,

clear, and exact description thereof, .which will enable those skilled in the art to-make and use the same, reference being had tothe accompanying drawing, forming part-of this speciloatiomin which- Figure 1 is a-view of the bolt and nut, the faced side of the nut toward you, and

Figure 2, a view of the bolt and nut, the face sid of the head toward you.

Similar'letters of reference inl ch of the figures u indicate corrresponding parts.

The object of my invention is to produce a bolt and nut that will not work loose, but will remain locked, l no matter how much jar there may be.

It is ofttimes the ease that the nut will remain firm,

yet the bolt will jar and turn, and rth us the bolt and nut l both become loose. In other cases the bolt will turn, when it is round, andthere is no chance to hold it when '-...screwinginpthe nnte Inboththese cases, my improvement, Vof corrugating or srrating-tle head oftheA bolt;A

obviates this difficulty, for the moment the nut draws on the bolt, theserrationssor 'coirngations take hold of the beariugand prevent the bolt from. turning, and when it'is screwed up solid, neither the bolt nor the nut. can turn. without shaving off some of the substantially as described.

surface, either under the head of the bolt or under the nut.

A is the holt, with the under side of the head corrugated or serrated, so that when the nut is set up it will hold without turning.

B, thel nnt, serlated ou the face, so that it will move up easily, but will not nnscrew without taking `a shaving oil" the material that it is screwed on to. 4

I sometimes. make the bolt and nut of steel, and

harden them'. I sometimes make them of iron, and

case-harden them. When to be used on wood-work,

make them of iron, without hardening.

Operation.

' J. B. SMITH. Witnesses:

H. s.- Loox,

Oms. A. SMITH. 

